Composition, film manufacturing method, as well as functional device and manufacturing method therefor

ABSTRACT

Disclosed are compositions, useful in ink jet printing methods, that prevent clogging during dispensing, achieve stable dispensing, prevent precipitating of content matter during dispensing, and prevent phase separation during film formation. Also disclosed are uniform, homogenous, functional films formed using the compositions and manufacturing methods therefor, as well as organic EL devices and other such display devices and manufacturing methods therefor. The compositions contain a functional material and a solvent comprising at least one benzene derivative having one or more substituents, whereby the substituents have at least three carbon atoms in total.

TECHNICAL FIELD

The present invention relates to a composition (dispensing composition),which is used to form a functional material patterned film, and can bestably dispensed using a dispensing apparatus, a film manufacturingmethod, which forms a uniform film (functional film) using thiscomposition, as well as a functional device comprising luminescentmaterial layers formed using the above-mentioned composition, andparticularly a functional device (display device), such as an organicelectroluminescent (EL) device, which is useful in luminescent displayapplications, and a manufacturing method therefor.

BACKGROUND ART

In the past, functional material patterning has been done usingphotolithography techniques. Because this method has drawbacks, such ashigh costs and complicated processes, recently, functional materialpatterning using a dispensing apparatus, which is convenient, and makescost cutting possible, has been under study. A method, which uses an inkjet printing apparatus, has been studied in particular.

For example, the manufacture of color filters for use with liquidcrystal displays can be raised as an example of micro-patterning usingan ink jet printing apparatus. This is a manufacturing method, whichappropriately ejects either dyed or pigmented ink of red, blue, andgreen in accordance with a printing apparatus having nozzles, whicheject ink of three colors, red, blue and green, producing a colorfilter. The ink used in this manufacturing method is ordinarilywater-soluble polar ink. In most cases, water-soluble ink such as thiscontains glycerin or some other solvent to prevent nozzle clog when theink dries.

Further, a method for making a luminescent material such as an organicfluorescent material, for example, into an ink, supplying this ink viadispensing onto a substrate using an ink jet method, and patterning theluminescent material is being used, and a color display device, and moreparticularly, an organic EL display device, which uses an organicluminescent material as a luminescent material, of a construction, inwhich a layer of this luminescent material is interposed between thepositive and negative electrodes, is being developed.

The manufacture of this color display device (organic EL display device)is, for example, carried out as follows.

Firstly, a fluorescent material is dissolved in a suitable solvent, andmade into ink. This ink (composition) is dispensed or ejected onto atransparent electrode-equipped substrate, which serves as the positiveelectrode of an organic EL display device, so as to cover thesetransparent electrodes. At this point, an electrode is either formed ona single plane, or has a strip- or mosaic-shaped pattern, and is astructure, which is connected to, and can be driven by a power source.Next, after forming a luminescent material layer by drying and removingthe solvent in the ink, a small, work function metal, for example, asilver, lithium, calcium, aluminum or other metal is expedientlydeposited on this luminescent material layer using a vapor deposition orsputtering method, forming a negative electrode. In this fashion, adisplay device of a structure in which this luminescent material layeris interposed between a positive and a negative electrode is achieved.

A pattern forming method using a conventional ink jet printing techniquesuch as this has extremely outstanding characteristics, such as savinglabor, saving resources, and not requiring mask making, but it also hasthe drawback of limiting the materials used in the composition(dispensing composition).

In the ink jet method, a solvent such as, for example, ethanol or wateris used as the solvent in the dispensing composition. However, amongnon-polar, or weakly polar functional materials, or polymer functionalmaterials (luminescent materials or the like), there are those that donot dissolve in these solvents. There is also the drawback thatfunctional materials, which either react with water and alcohol, or aredecomposed by alcohol, cannot be used.

Further, in a case in which benzene, toluene, xylene or another solventthat readily dissolves a non-polar material is used as the solvent fordissolving a functional material, due to the low boiling point (highvapor pressure) of such a solvent, the drawback is that it dries easily,and is apt to cause nozzle clog. Further, either during dispensing orafter dispensing, there are times in the formation of a film, when thedispensing composition is robbed of its heat of vaporization by thevolatilization of the solvent, and the temperature of the dispensingcomposition drops, promoting the precipitation of the functionalmaterial. In addition thereto, in the case of a functional materialhaving multiple constituents, the drawback is that phase separationoccurs, the film becomes non-uniform, and the functional film is nolonger able to carry out its original role.

Furthermore, in a case in which a material, which cannot be easily used,and has poor solubility like this, is used anyway, and the concentrationof the dispensing composition is increased, precipitation and cloggingoccur. When the concentration is made weaker in an attempt to preventclogging, the drawback is that dispensing must be performed numeroustimes to achieve the characteristics of the functional material, and thenumber of processes must be increased.

An object of the present invention is to provide a composition, whichcan be used in an ink jet printing method instead of a photolithographymethod, which is the conventional method for patterning a functionalmaterial, and can utilize a material that is either non-polar or weaklypolar, or a material of a reactivity that reacts easily with water.

Further, another object of the present invention is to provide acomposition, which prevents clogging at dispensing, achieves stabledispensing, and prevents precipitation of content matter duringdispensing and also prevents phase separation during post-dispensingfilm formation. Furthermore, another object of the present invention isto provide a uniform film (functional film) manufacturing method, and afunctional device (display device) such as an organic EL device, and amanufacturing method therefor.

DISCLOSURE OF THE INVENTION

The present invention achieves the above-mentioned objects by providinga composition, which is characterized in that it consists of afunctional material, and a solvent comprising at least one benzenederivative having one or more substituents, and these substituentshaving 3 or more carbon atoms in total.

Further, the present invention provides a film manufacturing method,which is characterized in that a film is formed using theabove-mentioned composition. Further, the present invention provides afunctional device comprising a luminescent material layer formed betweena first and a second electrode using the above-mentioned composition,and a manufacturing method therefor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an oblique view schematically showing a manufacturing processof a functional thin film and an organic EL device as a functionaldevice using a composition of the present invention;

FIG. 2 is a simplified cross-sectional view schematically showing aportion of the manufacturing processes of an organic EL device as afunctional device using a composition of the present invention(substrate formation process—hole injection/transport layer formationprocess); and

FIG. 3 is a simplified cross-sectional view schematically showing aportion of the manufacturing processes of an organic EL device as afunctional device using a composition of the present invention(luminescent layer formation process—sealing process).

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinbelow, a composition, film manufacturing method, as well as afunctional device and a manufacturing method therefor of the presentinvention will be explained in detail.

A composition of the present invention is characterized in that itconsists of a functional material and a solvent comprising at least onebenzene derivative, which has one or more substituents, and thesesubstituents have 3 or more carbon atoms in total.

Furthermore, what is referred to here as “these substituents have 3 ormore carbon atoms in total” means that the total number (sum) of carbonatoms of all the displaceable substituents in a benzene derivative is 3or more. Therefore, for example, even when one substituent is a methylgroup or an ethyl group having 1 or 2 carbon atoms, if combining thiswith another substituent constitutes 3 or more carbon atoms, then thiscombination can be incorporated in the above-mentioned benzenederivative related to the present invention.

The above-mentioned benzene derivative utilized in the composition ofthe present invention has one or more substituents as explainedhereinabove. As one of these substituents, there are no particularlimitations as long as the total number of carbon atoms of all thesubstituents constitutes 3 or more. As examples, either a normal chainor branched aliphatic hydrocarbon group, alicyclic hydrocarbon group, oraromatic hydrocarbon group can be given, and furthermore, oxygen atoms,nitrogen atoms, sulfur atoms and other hetero atoms can be contained inthese hydrocarbon groups. Further, the respective substituents can alsobond together to form a cycloalkane ring or other ring structure.

Further, as for the above-mentioned benzene derivative, the number ofcarbon atoms thereof is 3 or more as mentioned above, but from thestandpoint of being able to further improve the solubility of anon-polar or weakly polar functional material, this number is preferablybetween 3 and 12, and more preferably, between 3 and 6.

The above-mentioned benzene derivative is used in a composition of thepresent invention as a solvent, which at least comprises this benzenederivative. As such a solvent, either a single solvent consisting of the1 benzene derivative given as an example hereinabove, or a mixed solventconsisting of two or more these benzene derivatives will be acceptable,and a mixture of the above-mentioned benzene derivative and a solventother than the above-mentioned benzene derivative will also beacceptable.

Here, as solvents other than the above-mentioned benzene derivative, inaddition to a benzene derivative having 1 or more substituents ofxylene, toluene or the like, with the total number of carbon atoms ofthese substituents being 2 or less (under 3), or a non-displaceablebenzene compound, a displaceable benzene compound with a substituentthat does not comprise carbon atoms can be given as an example.

As a functional material used in a composition of the present invention,there are no particular limitations, and even if it is a non-polar orweakly polar material, or a material of a reactivity that readily reactswith water, it can be utilized. As such a functional material, amaterial, which accords with the application of a composition of thepresent invention, is utilized, and an organic EL material or otherluminescent material, a silica glass precursor, a color filter material,an organic metal compound or other conductive material, and either adielectric or semiconductor material can be given as examples. Anorganic EL material, silica glass precursor, and color filter materialare especially favorable.

A composition of the present invention will be utilized in a variety ofapplications, but ideally it will be used in ink jet methods inparticular.

If a composition that requires the above-mentioned benzene derivative ofthe present invention is used, soluble material selectivity inparticular will become broader, drying will be prevented at least duringdispensing, stable dispensing will be made possible, and a uniform,homogenous, micro film (functional film) will be achieved. To producethis excellent film, the above-mentioned composition of the presentinvention is supplied via dispensing and distributed on a substrate, andthereafter, this film is produced by subjecting this substrate to heattreatment (heating). Specifically, there can be cited a method, bywhich, after a composition of the present invention has been dispensedand distributed on a substrate by a dispensing apparatus, the substrateis treated at a temperature that is higher than the temperature atdispensing. In general, the dispensing temperature is room temperature,and the substrate is heated after dispensing. By carrying out this kindof treatment, the content matter, which precipitated due to a drop intemperature resulting from post-dispensing solvent volatilization, isre-dissolved, and a uniform, homogenous film can be obtained withoutphase separation.

As for the temperature of the heat treatment, little effect is noticedin the vicinity of room temperature, but effects become evident at 40°Centigrade and higher. When the temperature exceeds 200° C., the solventevaporates as soon as heat is applied, and the effect of heating islost. Based on the above, the ideal heat treatment temperature isbetween 40° and 200° C. More preferably, by heating at 50-200° C., amore uniform, homogenous functional film can be obtained. The followingeffects are obtained by such a heat treatment temperature setting. Inthe case of dispensing or ejecting a composition (ink) via an ink jetmethod in particular, generally, the solvent is vaporized, thetemperature of the ink droplets is lowered, and content matterprecipitation is a possibility. When the content matter of the inkconstitutes 2 constituents or more, there are cases in which the inkchanges from a homogenous mixture system to a non-homogenous mixturesystem. In this case, phase separation occurs inside the luminescentmaterial, and the chromaticity and luminous efficiency achieved via ahomogenous system is not obtained. Accordingly, performing heattreatment by applying heat in the above-mentioned temperature range hasthe effect of re-dissolving the content matter of the dispensedcomposition, and making it more homogenous.

Further, when manufacturing a film, not only heat treatment (heating),but also reduced pressure, pressurization, or a combination of thesewith heating can be used as needed.

For example, as a reduced pressure and heating combination, after heattreatment, it is desirable that pressure be reduced as-is immediately,thus removing the solvent. As for the pressure when reducing pressure,from the standpoint of being able to achieve a more uniform, homogenousfunctional film, preferably this pressure is 20×10⁻³ mmHg (Torr) orless. By so doing, it is possible to prevent phase separation of thecontent matter when concentrating a composition. That is, when a oncere-dissolved content matter is concentrated, solvent is suddenlyeliminated, and by uniformly affixing the content matter before samebecomes non-homogenous, the non-homogenization (phase separation) of thecontent matter is prevented, and the desired luminescent intensity andchromaticity initially targeted can be achieved in the formedluminescent material layer.

Further, the time from the start of heat treatment until the point intime when pressure reduction commences is established in accordance withthe dispensing volume and material characteristics.

As a dispensing apparatus, which uses a composition of the presentinvention in an ink jet method, and which is used in the production ofthe above-mentioned film (functional film), an ink jet printingapparatus, and a dispenser can be cited, the ink jet printing apparatusbeing preferable.

Further, if a composition of the present invention is used, anoutstanding functional device, such as an organic EL device, which isparticularly useful in luminescent display applications, can beachieved. Specifically, a display device comprising a luminescentmaterial layer (emitting material layer) formed between a first andsecond electrode using the above-mentioned composition of the presentinvention (preferably, a hole injection/transport layer will also beestablished between the above-mentioned first electrode and theabove-mentioned luminescent material layer) is achieved.

Here, hole injection/transport layer refers to a layer having a functionfor injecting an electron hole or other hole inside, and, in addition,having a function for transporting an electron hole or other hole on theinside. Providing this kind of hole injection/transport layer isdesirable for improving the luminous efficiency, life and other devicecharacteristics of an organic EL device in particular.

Furthermore, as a functional device, in addition to a thin, lightweight,low power consumption, high angle of visibility multicolor displaydevice, which uses an organic luminescent material, for example, anorganic EL device, there can be cited a display, which has a pluralityof pixels, and in which a thin film transistor or other switching deviceis provided for each pixel.

In manufacturing a display device as this outstanding functional device,manufacture is carried out by selectively supplying the above-mentionedcomposition of the present invention onto a substrate having a firstelectrode, and preferably, forming a luminescent material layer patternby either heating, reducing pressure, or pressurizing, or by combiningthese with heating, and next, forming a second electrode on thisluminescent material layer pattern (Preferably, after forming via an inkjet method using a solution comprising a polar solvent a holeinjection/transport layer on the above-mentioned substrate, which has afirst electrode, more preferably, the above-mentioned luminescentmaterial layer pattern is formed on this hole injection/transport layerusing a solution, which utilizes a non-polar solvent.). In this manner,it is possible to achieve an outstanding organic EL device.

It is preferable that the luminescent material layer as functional film,which utilizes a composition of the present invention in theabove-mentioned functional device, be formed in accordance with themanufacturing method of the above-mentioned film (functional film).

Further, as the solution (composition) comprising a polar solvent, whichis utilized when forming a hole injection/transport layer, there can becited polythiophene derivatives, such as polyethylene dioxythiophene,and solutions, which mix constituents, such as polystyrene sulfonicacid, into polar solvents, such as α-butyrolactone, N-methylpyrolidone,1,3-dimethyl-2-imidazolidinone and derivatives thereof, carbitolacetate, butyl carbitol acetate and other glycol ethers. Using a polarsolvent such as this is desirable for enabling stable dispensing withoutnozzle clog, and for excellent film formability.

Hereinbelow, compositions of the present invention will be explained indetail based on the preferred embodiments therefor.

FIRST EMBODIMENT

A first embodiment of a composition of the present invention is acomposition, which is utilized in functional material pattern filmformation using a dispensing apparatus, and is a composition comprisinga functional material and a solvent comprising at least one benzenederivative, which has 1 or more substituents, and these substituentshave 3 or more carbon atoms in total.

According to this embodiment, the effects are that a non-polar or weaklypolar functional material can be readily dissolved, and functionalmaterial selectivity can be broadened, and, in addition, especially in acase in which a solvent with a relatively low vapor pressure is used,from the standpoint of delayed drying capabilities, clogging isprevented at solvent dispensing time, and stable dispensing is madepossible, and it is possible to achieve the prevention of content matterprecipitation and phase separation during post-dispensing film formationin accordance with either subsequent heating, or by combining heatingwith a treatment, such as pressurizing, or heating followed immediatelyby reducing pressure.

As a solvent, which is compatible with the first embodiment, and whichcomprises at least one benzene derivative having 1 or more substituents,with these substituents having 3 or more carbon atoms in total, therecan be considered either single solvents, such as cumene, cymene,cyclohexylbenzene, dodecylbenzene, diethylbenzene, pentylbenzene,dipentylbenzene, butylbenzene, tetralin, and tetramethylbenzene, ormixtures of these solvents. Or xylene, toluene, benzene and the like canbe added to these single solvents, or mixed solvents as required bycircumstances. By utilizing single solvents or mixed solvents like thosegiven as examples here, a composition in which there is dissolved anon-polar or a weakly polar functional material becomes a possibility.That is, material selectivity broadens. Further, utilizing a singlesolvent or a mixed solvent like this enables the prevention of clogging.

It is preferable that the boiling point of the benzene derivativeutilized in a composition of the first embodiment by 200° C. or higher.Solvents such as this include dodecylbenzene, cyclohexylbenzene,tetralin, dipentylbenzene, and pentylbenzene. Utilizing these solventsis even more favorable as it enables the further prevention of solventvolatilization.

It is preferable that dodecylbenzene be the benzene derivative utilizedin a composition of the first embodiment. As a dodecylbenzene, a singlen-dodecylbenzene is fine, and a mixture of isomers is also fine.

This solvent has characteristics such as a boiling point of over 300°C., and viscosity of 6 mPa·s or more (20° C.), and this solvent alone isof course fine, but adding it to another solvent is good for preventinga composition from drying. Further, of the solvents mentioned above,since the viscosity of those other than dodecylbenzene is relativelysmall, dodecylbenzene is extremely good because adding this solvent tothe others enables viscosity adjustment.

As a functional material, which is compatible with the first embodiment,an organic EL material can be considered. In particular, it is desirablethat the organic EL material comprise a material that is eithernon-polar, or weakly polar. For example, an EL material comprising aderivative of a (poly)praraphenylene vinylene system, polyphenylenesystem, polyfluorene system, or polyvinyl carbazole system, a lowmolecular weight organic EL material capable of being dissolved inanother benzene derivative, and a high molecular weight EL material canbe considered. For example, it will also be possible to use rubrene,perylene, 9,10-diphenyl anthracene, tetraphenyl butadiene, nile red,coumarin6, quinacridone, and a polythiophene derivative. Further, thesematerials can also be used for electron transportable and holetransportable materials, which are peripheral materials of an organic ELdisplay.

Further, as a functional material compatible with the first embodiment,in addition to the above-mentioned organic EL material, polysilazane(made by Tonen, for example), which is the silicon glass precursorsubstance of an interlayer insulation layer that has numerous uses in asemiconductor, and an organic silicon-on-glass (SOG) material can alsobe considered.

Furthermore, it is also desirable that the functional material forforming a composition of the first embodiment be a material for a colorfilter. As this color filter material, various kinds of sublimation dyescan be selected, such as, for example, sumika red B (brand name of a dyemanufactured by Sumitomo Chemical Co., Ltd.), kayaron fast yellow-GL(brand name of dye manufactured by Nihon Kayaku Co., Ltd.), anddaiaserin fast brilliant blue-B (brand name of dye manufactured byMitsubishi Kasei Corporation).

And furthermore, organic metal compounds can also be used as functionalmaterials. Or, if it is a material that will dissolve in theabove-mentioned solvents, then any kind of functional material can beused as a composition.

By using a composition of the first embodiment, it is possible toprepare a functional film, such as a functional material patterned film,using a dispensing apparatus. The preparation method for this functionalfilm can be performed in accordance with the above-mentioned filmmanufacturing method. That is, a functional film can be obtained bysupplying via dispensing and distributing a composition of the firstembodiment on a substrate, and thereafter, subjecting this substrate toheat treatment preferably at 40° C.-200° C. In the first embodiment inparticular, setting this heat treatment temperature to 50° C.-200° C. iseven more preferable for enabling the realization of a more uniform,homogenous functional film. Further, in the first embodiment, it isdesirable to apply heat while applying pressure during high temperaturetreatment. By so doing, it is possible to delay the volatilization ofthe solvent at heating, making the re-dissolving of the content mattereven more complete. As a result thereof, it is possible to obtain a moreuniform, homogenous functional film. From the standpoint of producing aneven more uniform, homogenous functional film, preferably the pressureapplied is 1520-76000 mmHg (2-100 atmospheres).

Further, in the heat treatment of a composition of the first embodiment,it is desirable to remove the solvent by reducing pressure as mentionedabove prior to the composition becoming completely dry.

As a dispensing apparatus capable of using a composition of the firstembodiment, an ink jet printing apparatus, dispenser or the like can beutilized, but an ink jet printing apparatus is desirable due to thefineness and precision thereof, and by utilizing this ink jet printingapparatus, it is possible to manufacture a micro functional film easilyand at low cost.

By using a composition of the first embodiment, it is possible toobtain, in a preferable manner, an organic EL device or other suchdisplay device, which is useful as the above-mentioned functional device(preferably, a display device having a hole injection/transport layerprovided between the above-mentioned first electrode and above-mentionedluminescent material layer.).

SECOND EMBODIMENT

A second embodiment of a composition of the present invention is acomposition containing a solvent comprising at least dodecylbenzene, anda polyfluorene derivative of at least 1 of the compounds 1 through 5hereinbelow. That is, the second embodiment is a composition, whichutilizes a solvent, which is compatible with the second embodiment in acomposition of the present invention, and which comprises at leastdodecylbenzene as a solvent comprising a benzene derivative having 1 ormore substituents, and these substituents have 3 or more carbon atoms intotal, and which utilizes a polyfluorene derivative of at least 1 of thecompounds 1 through 5 as a functional material that is compatible withthe second embodiment.

This embodiment is a more preferred aspect than the first embodimentexplained hereinabove, and from the standpoint of using the low vaporpressure solvent dodecylbenzene, and having delayed drying capabilities,can prevent clogging at solvent dispensing, and can ensure stabledispensing, and in particular, preferably has the effect of making itpossible to achieve a uniform film without phase separation by eitherapplying heat and pressure, or reducing pressure immediately afterheating, which will be explained hereinbelow.

Because this embodiment, as mentioned hereinabove, is a more preferredversion of the first embodiment, with regard to points that are notexplained in particular detail in the description for the secondembodiment, the detailed description regarding the above-mentioned firstembodiment will be applied as the occasion demands.

The second embodiment will be explained in detail. A composition of thisembodiment, by using dodecylbenzene as the solvent thereof, makes itpossible to prevent excessive drying when dispensing from an ink jethead, and in particular, enables the prevention of clogging in an inkjet head because the delayed drying effect of this dodecylbenzene ismanifested in a case in which this composition is utilized as an inkcomposition when forming a pattern using an ink jet method. Further,even after dispensing, the dispensed material remains in liquid form onthe material targeted for dispensing, making possible post-treatment,such as heating. Furthermore, the above-mentioned special structurepolyfluorene derivatives (compounds 1 through 5) are prepared asluminescent materials, have strong luminous intensity, and due to theirbeing weakly polar, have good solubility for dodecylbenzene, andaccording to combining this luminescent material with a solvent, arecapable of good patterning as a component member of an organic ELdisplay device in particular.

In a composition of the second embodiment, a variety of second solventscapable of dissolving a luminescent material in dodecylbenzene can bemixed with the composition and utilized as a solvent. Preferably, asolvent with a boiling point of 140° C. or higher is mixed in andutilized. As such a second solvent with a boiling point of 140° C.,cymene, tetralin, cumene, decalin, durene, cyclohexylbenzene,dihexylbenzene, tetramethylbenzene, dibutylbenzene and the like can beutilized. It is especially desirable to utilize a solvent having acompound, which has substituents of 3 or more carbon atoms in a benzenering. Further, it is preferable to utilize a solvent with a boilingpoint of 180° C. or higher, such as tetralin,1,2,3,4-tetramethylbenzene, 1,2,3,5-tetramethylbenzene,cyclohexylbenzene, decalin, and dibutylbenzene. By adding thesesolvents, it is possible to adjust the concentration and drying rate ofan ink composition. It also has the effect of reducing the highviscosity of dodecylbenzene. Furthermore, a composition that utilizestetralin as a solvent having the above-mentioned 180° C. or higherboiling point has the advantage of making it possible to increase theconcentration thereof. In addition, toluene, xylene, chloroform, andcarbon tetrachloride can be utilized as a solvent.

As a luminescent material that serves as a functional material inconformance to the second embodiment, in addition to the above-mentionedspecific polyfluorene derivative, a (poly)praraphenylene vinylenederivative, polyphenylene derivative, polyvinyl carbazole derivative,polythiophene derivative, perylene system pigment, coumarin systempigment, rhodamine system pigment, and non-polar or weakly polarmaterials are suitable, but in addition, a low molecular weight organicEL material and a polymer organic EL material, which are capable ofdissolving in a benzene derivative, can also be used. For example, itwill also be possible to use rubrene, perylene, 9,10-diphenylanthracene, tetraphenyl butadiene, nile red, coumarin6, quinacridone,and the like. Further, it is also possible to make appropriate use of ahole transport material and an electron transport material, whichconstitute an organic EL display device.

Further, as the above-mentioned luminescent material, a compound (6)having the below structure can also be added.

By using a composition of the second embodiment, ideally it is possibleto obtain an organic EL device or other such display device, which isuseful as the above-mentioned functional device (preferably, a displaydevice comprised by providing a hole injection/transport layer betweenthe above-mentioned first electrode and above-mentioned luminescentmaterial layer.) just like with the above-mentioned first embodiment.

When preparing the above-mentioned luminescent material layer using acomposition of the second embodiment, for example, this composition isdispensed and distributed on a substrate by a dispensing apparatus asdescribed hereinabove, and thereafter, the substrate is subjected toheat treatment at a temperature that is higher than the temperature atdispensing (preferably, between 40°-200°). The heat treatment process isbetter the higher the temperature at which it is performed, but in acase in which a low boiling point solvent is utilized, there is thedanger that drying will be completed immediately following dispensingand the advantages of this process will not be fully realized. Accordingto this example, because dodecylbenzene, a high boiling point solvent,is utilized, the content matter of a dispensed composition isre-dissolved by the heat treatment, making the above-mentioned effect ofgreater uniformity superb.

It is preferable that the above-mentioned heat treatment of thecomposition be carried out at the same temperature as in the case of theabove-mentioned first embodiment. Further, it is desirable that theabove-mentioned heat treatment of the composition be carried out underapplied pressure the same as the above-mentioned first embodiment, andfurthermore, it is desirable that in the above-mentioned heat treatmentof the composition the solvent be removed by reducing pressure prior tothe composition drying completely.

THIRD EMBODIMENT

A third embodiment of a composition of the present invention is acomposition consisting of a functional material and a solvent comprisingat least 1 benzene derivative, which has 1 or more substituents, andthese substituents have 3 or more carbon atoms in total, and which has avapor pressure (at room temperature; the same hereinbelow) of between0.10 and 10 mmHg. That is, the third embodiment is a composition, whichutilizes a solvent, which is compatible with the third embodiment in acomposition of the present invention, and which comprises at least onebenzene derivative with a vapor pressure of between 0.10 and 10 mmHg asa solvent comprising at least one benzene derivative having 1 or moresubstituents, with these substituents having 3 or more carbon atoms intotal.

According to this embodiment, the effects are obtained that a non-polaror weakly polar functional material can be readily dissolved, and, inaddition, clogging is prevented at solvent dispensing time, and stabledispensing is made possible, and it is possible to achieve theprevention of content matter precipitation at dispensing and phaseseparation during post-dispensing film formation. In particular, ifusing a solvent of a vapor pressure of the above-mentioned scope, thereare achieved characteristics whereby drying is difficult to a certaindegree, thus achieving a balance such that the material dries rapidlyenough so that phase separation does not occur, and a film is formedwithout phase separation via natural drying at room temperature.

As a solvent, which is utilized in a composition of the thirdembodiment, and which comprises at least 1 benzene derivative of theabove-mentioned vapor pressure of between 0.10 and 10 mmHg, there can becited 1,2,3,4-tetramethylbenzene, 1,2,3,5-tetramethylbenzene,cyclohexylbenzene, pentylbenzene, mesitylene, cumene, cymene,diethylbenzene, tetralin, and decalin, and of these,1,2,3,4-tetramethylbenzene is especially preferable.

Further, as the above-mentioned benzene derivative, a mixture of atleast 1 benzene derivative of a 0.10-0.50 mmHg vapor pressure, and atleast 1 benzene derivative of a 0.50-10 mmHg vapor pressure is alsopreferable.

Here, as the above-mentioned benzene derivative of a 0.10-0.50 mmHgvapor pressure, either tetramethylbenzene or cyclohexylbenzene ispreferable.

Further, as the above-mentioned benzene derivative of a 0.50-10 mmHgvapor pressure, diethylbenzene and/or mesitylene is preferable.

There are no particular limitations as to a functional material, whichis compatible with a composition of the third embodiment, and, forexample, the above-mentioned organic EL material, and silicon glassprecursor material can be applied to this embodiment, and, inparticular, at least 1 polyfluorene derivative, especially theabove-mentioned compounds 1-5, which are utilized in a composition ofthe second embodiment described hereinabove, is ideal. Therefore, as afunctional material utilized in this embodiment, a luminescent materialthat serves as a functional material, which was described in theabove-mentioned second embodiment, is applied according tocircumstances.

Further, a composition of the third embodiment can achieve a specificoutstanding device by removing residual solvent after film formation viaeither heating, or a combination of heating and pressure reduction. Itis preferable that the heating temperature at this time be 40° C.-200°C., and more preferably 50° C.-100° C. Further, it is desirable that thepressure at reduced pressure be 20×10⁻³ mmHg or less. Further, afterdispensing (after dispensing ink to the entire surface of a substrate),a film can be formed under either heating or a combination of heatingand reduced pressure, even if droplets remain.

By using a composition of the third embodiment, the same as in theabove-mentioned first and second embodiments, ideally it is possible toobtain an organic EL device or other such display device, which isuseful as the above-mentioned functional device (preferably, a displaydevice comprised by providing a hole injection/transport layer betweenthe above-mentioned first electrode and above-mentioned luminescentmaterial layer.)

The present invention will be explained more concretely hereinbelow byreferring to the examples. However, the present invention is in no waylimited to these examples.

Examples of First Embodiment Example 1-1

A tetrahydrofuran solution of a polyvinyl carbazole was applied to theelectrode side of a glass substrate equipped with a transparentindium-tin-oxide (ITO) electrode, and a 0.1 micrometer polyvinylcarbazole film was formed via a spin coating method. On this film, a 0.1percentage by weight xylene/tetralin mixed solution ofpolyhexyloxyphenylene vinylene (xylene/teralin=¼ percentage by volume)was dispensed in a prescribed shape using an ink jet printing apparatus.Furthermore, aluminum was deposited on top thereof.

Lead wires were derived from the ITO and aluminum, and with the ITO asthe positive electrode and the aluminum as the negative electrode, anorange light was emitted in a prescribed shape upon the application of avoltage of 10 volts. In a case in which conventional ink, which usedonly xylene as a solvent, was dispensed, drying was rapid, cloggingoccurred, and the ink jet printing apparatus soon became unusable,whereas according to this method, clogging ceased to occur.

Example 1-2

A polysilazane solution of 20 weight percent of xylene (manufactured bythe Tonen Chemical Corporation) was mixed together with a mixed solutionof cymene and tetralin (cymene/tetralin=1/1) so as to constitute 20percent by volume of a mixed solvent. The thus obtained polysilazanesolution was dispensed via an ink jet printing apparatus so as to coverthe entire surface of a plastic liquid crystal panel, and allowed todry. This same process was performed on the opposite side, forming apolysilazane film on both sides of the panel. This panel was placed inan 85° C., 90 percent thermo-hygrostat for 20 minutes, forming asilica-glass film. After removing this panel, and allowing it to dry, 2polarizing plates were laminated from both sides so as to be orthogonal.

In accordance with this method, much less polysilazane was used thanwith the spin coating method, making possible the formation of asilica-glass film with practically no loss. Further, the gaspermeability of the liquid crystal panel was improved, and the life ofthe liquid crystal panel was also improved.

Example 1-3

A polysilazane solution of 20 weight percent of xylene (manufactured bythe Tonen Chemical Corporation) was mixed together with a mixed solutionof cymene and tetralin (cymene/tetralin=1/1) so as to constitute 20percent by volume of a mixed solvent. The thus obtained polysilazanesolution was dispensed via an ink jet printing apparatus, and applied tothe entire surface of a silicon substrate, which had been furnished withsemiconductor device formations and aluminum wiring. After application,the substrate was dried at 150° C. for 20 minutes, and thereafter, bakedfor 2 hours at 350° C. in a steam environment.

As a result thereof, a planarized film was obtained using silica glassof roughly the same properties as when a spin coating method is used.However, 2 orders of magnitude less polysilazane was used.

Example 1-4

An aspect of this example of the present invention will be explained inmore detail. As shown in FIG. 1, the below-described dispensingcompositions, in which have been dissolved organic EL materials thatemit the colors red, green and blue, are ejected and distributed by anink jet printing apparatus so as to be arrayed in a mosaic of each coloron transparent ITO (indium-tin-oxide) electrodes partitioned into amosaic, and an electrode of a glass substrate equipped with bankssurrounding the transparent electrodes. The ratio of the solid relativeto the solvent in all cases is 0.4% (weight/volume). In FIG. 1, 1indicates a nozzle, 2 indicates a glass substrate, 3 indicates atransparent ITO electrode, 4 indicates a bank (partition), and 5indicates a composition (ink droplet), respectively.

<Dispensing Composition>

Solvent: Dodecylbenzene/tetralin (1/1, volume percentage)Red: Polyfluorene/perylene dye (98/2, percentage by weight)Green: Polyfluorene/coumarin dye (98.5/1.5, percentage by weight)

Blue: Polyfluorene

The substrate obtained by ejecting the composition was heated at 100° C.and the solvent was removed, and thereafter, an appropriate metal maskwas placed on this substrate, and 2000 Angstroms of aluminum wasdeposited thereon.

Lead wires were derived from the ITO and aluminum, and with the ITO asthe positive electrode and the aluminum as the negative electrode, red,green and blue colors were emitted in a prescribed shape upon theapplication of a voltage of 15 volts. In a case in which conventionalink, which used only xylene as a solvent, was dispensed, drying wasrapid, clogging occurred, and the ink jet printing apparatus soon becameunusable, whereas according to this method, clogging ceased to occur.Further, since the substrate was heated after dispensing the inkcomposition and the content matter re-dissolved, the separation of thecontent matter was prevented, and there were no problems whatsoever inthe emission spectrum. A case in which xylene or some other low boilingpoint solvent was utilized was not preferable because drying commencedimmediately after dispensing, content matter precipitated and phaseseparation occurred due to heat of vaporization, and changes occurred inthe emission spectrum.

If each of the above-mentioned ITO electrodes were to be connected to athin-film transistor (TFT) device, it would be possible to produce viaorganic EL a display that is the same as a liquid crystal displaycurrently in circulation.

Example 1-5

After drying for 1 minute at 100° C. a substrate that had been subjectedto ejecting the same as in Example 1-4, the solvent was removed byimmediately reducing the pressure (2 mmHg). Utilizing the resultingsubstrate, a panel was produced by the same method as Example 1-4, andupon being lighted, the same results as in Example 1-4 were achieved.

Example 1-6

A substrate that had been subjected to dispensing the same as in Example1-4 was set in a bell jar, the bell jar was filled with nitrogen gas andthe internal pressure was set a 2 atmospheres, the substrate was driedat 100° C., and the solvent was removed. Utilizing the resultingsubstrate, a panel was produced by the same method as Example 1-4, andupon being lighted, the same results as in Example 1-4 were achieved.

Examples of Second Embodiment Example 2-1

In this example, a color display device will be manufactured.

With regard to the processes in this example, these can be explainedusing FIG. 1 the same as the examples of the first embodiment describedhereinabove. That is, in the structure shown in FIG. 1, a transparentITO electrode 3 is formed in a dot-shaped pattern, each dot is directlyconnected to an independent TFT device (not shown in the figure), formsa pixel, and can be driven. A bank 4 is formed at the boundary portionof each pixel (dot of the transparent ITO electrode 3) so as topartition each pixel, a composition (ink composition) 5 ejected from anozzle is supplied and adheres to the top of the transparent ITOelectrode partitioned by banks 4. By using luminescent materials ofthree colors in the compositions, a multicolored luminescent display canbe produced.

First, as compositions (ink compositions) three compositions wereprepared by mixing luminescent materials with solvents in theprescriptions shown in Table 1 hereinbelow. The luminescent materialsare selected from among compounds 1 through 5, which are characterizedby the present invention described hereinabove, and furthermore,compound 6 is utilized as needed.

Next, using an ink jet apparatus, these compositions were ejected onto asubstrate (TFT substrate), which had banks 4 consisting of a polyimide,and for which a TFT was provided for each pixel. The size of an areasubjected to ejecting (area partitioned by banks 4) was 30 μm×30 μm, thepitch was 70 μm, and the pitch of the ejecting of the compositions (inkcompositions) was set at 70 μm. Dispensing was satisfactorily performedwithout any clogging occurring in the ink jet heads, making it possibleto obtain a substrate on which three inks were arranged in a mosaicshape.

TABLE 1 Luminescent Materials Solvents R (Red) ink Compound 1 0.70 gDodecylbenzene Compound 2 0.2 g 100 ml Compound 6 0.1 g Tetralin 100 mlG (Green) ink Compound 1 0.76 g Dodecylbenzene Compound 2 0.2 g 100 mlCompound 4 0.04 g Tetralin 100 ml B (Blue) ink Compound 1 0.78 gDodecylbenzene Compound 2 0.15 g 100 ml Compound 3 0.07 g Tetralin 100ml

A luminescent layer was achieved by subjecting this substrate to heattreatment on a hot plate at 100° C. in a nitrogen environment. The filmthickness of the produced luminescent layer or emitting layer was0.08-0.1 μm. In addition, lithium fluoride (100 nm), calcium (100 nm)and aluminum (150 nm) were deposited in that order on the luminescentlayer, the resulting laminate structure was sealed in epoxy resin, andan organic EL display device was achieved.

Upon driving the TFT device provided on each transparent ITO electrode(dot) at 10 volts, it was possible to display a desired color in a pixel(a color equivalent to the luminescent layer provided on this pixel).Further, motion pictures could also be displayed. In particular, in apixel in which G ink had been ejected, the peak ratio of 440 nm and 530nm of the luminous wavelength spectrum (440 nm/530 nm) measured 1.0, andvisually the green was displayed well.

Example 2-2

Three compositions (ink compositions) were prepared by mixingluminescent materials with solvents in the compositions shown in Table 2hereinbelow and, in the same way as Example 2-1, using an ink jetapparatus, these compositions were ejected onto a substrate (TFTsubstrate) having banks 4 consisting of polyimide as shown in FIG. 1.The size of an area subjected to ejecting (area partitioned by banks 4)was 30 μm×30 μm, the pitch was 70 μm, and the pitch of the ejecting ofthe compositions (ink compositions) was set at 70 μm. Dispensing wassatisfactorily performed without any clogging occurring in the ink jetheads, making it possible to obtain a substrate on which three inks werearranged in a mosaic shape.

TABLE 2 Luminescent Materials Solvents R (Red) ink Compound 1 0.70 gDodecylbenzene Compound 2 0.2 g 100 ml Compound 5 0.1 g Tetralin 100 mlG (Green) ink Compound 1 0.76 g Dodecylbenzene Compound 2 0.2 g 100 mlCompound 4 0.04 g Tetralin 100 ml B (Blue) ink Compound 1 0.78 gDodecylbenzene Compound 2 0.15 g 100 ml Compound 3 0.07 g Tetralin 100ml

A luminescent layer was achieved by subjecting this substrate to heattreatment on a hot plate at 100° C. in a nitrogen environment. The filmthickness of the produced luminescent layer was 0.08-0.1 μm. Inaddition, lithium fluoride (100 nm), calcium (100 nm) and aluminum (150nm) were deposited in that order on the luminescent layer, the resultinglaminate structure was sealed in epoxy resin, and an organic EL displaydevice was achieved.

Upon driving the TFT devices provided on each transparent ITO electrode(dot) at 10 volts, it was possible to display a desired color in a pixel(a color equivalent to the luminescent layer provided on this pixel).Further, motion pictures could also be displayed. In particular, in apixel in which G ink had been ejected, the peak ratio of 440 nm and 530nm of the luminous wavelength spectrum (440 nm/530 nm) measured 1.0, andthe green was displayed well visually.

Example 2-3

The same as in Example 2-1, first three compositions (ink compositions)of the compositions shown in Table 1 above were prepared, and using anink jet apparatus, these inks were ejected onto a TFT substrate havingbanks 4 consisting of polyimide as shown in FIG. 1. Dispensing wassatisfactorily performed without any clogging occurring in the ink jetheads.

A luminescent layer was achieved by subjecting this substrate to heattreatment on a hot plate for 1 minute at 100° C. in a nitrogenenvironment, immediately reducing pressure (1 mmHg mercury column), andremoving the solvent. The film thickness of the resulting luminescentlayer was 0.08-0.1 μm. In addition, lithium fluoride (100 nm), calcium(100 nm) and aluminum (150 nm) were deposited in that order on theluminescent layer. The resulting laminate structure was sealed in epoxyresin, and an organic EL display device was achieved.

Upon driving the TFT devices provided on each transparent ITO electrode(dot) at 10 volts, it was possible to display a desired color in a pixel(a color equivalent to the luminescent layer provided on this pixel).Further, motion pictures could also be displayed. In particular, in apixel in which G ink had been ejected, the peak ratio of 440 nm and 530nm of the luminous wavelength spectrum (440 nm/530 nm) measured 1.8, andthe green color display was even better.

Example 2-4

The same as in Example 1, first three compositions (ink compositions) ofthe compositions shown in Table 1 above were prepared, and using an inkjet apparatus, these inks were ejected onto a TFT substrate having banks4 consisting of polyimide as shown in FIG. 1. Dispensing wassatisfactorily performed without any clogging occurring in the ink jetheads.

A luminescent layer was achieved by subjecting this substrate to heattreatment on a hot plate for 1 minute at 150° C. in a 2-atmospherenitrogen environment, immediately reducing pressure (1 mmHg mercurycolumn), and removing the solvent. The film thickness of the resultingluminescent layer was 0.08-0.1 μm. In addition, lithium fluoride (100nm), calcium (100 nm) and aluminum (150 nm) were deposited in that orderon the luminescent layer. The resulting laminate structure was sealed inepoxy resin, and an organic EL display device was achieved.

Upon driving the TFT devices provided on each transparent ITO electrode(dot) at 10 volts, it was possible to display a desired color in a pixel(a color equivalent to the luminescent layer provided on this pixel).Further, motion pictures could also be displayed. In particular, in apixel in which G ink had been ejected, the peak ratio of 440 nm and 530nm of the luminous wavelength spectrum (440 nm/530 nm) measured 2.0, andgreen was displayed even better.

Example 2-5

Three compositions (ink compositions) were prepared by mixing 100 ml ofcyclohexylbenzene in place of tetralin in the compositions shown inTable 2-2 above, with the other luminescent materials being the same,and mixing these luminescent materials with a solvent, and the same asin Example 2-1, using an ink jet apparatus, and ejecting these inks ontoa TFT substrate having banks 4 consisting of polyimide as shown inFIG. 1. Ejecting was performed at a pitch of 70 μm and a substrate onwhich three inks were arranged in a mosaic shape was obtained.

This substrate was subjected to heat treatment on a hot plate at 130° C.in a nitrogen environment. The film thickness of the resultingluminescent layer was 0.08-0.1 μm. In addition, lithium fluoride (100nm), calcium (100 nm) and aluminum (150 nm) were deposited in that orderon the luminescent layer.

Upon driving the TFT devices provided on each transparent ITO electrode(dot) at 10 volts, it was possible to display a desired color in a pixel(a color equivalent to the luminescent layer provided on this pixel).Further, motion pictures could also be displayed.

Example 2-6

Three compositions (ink compositions) were prepared using the samecompositions as in Example 2-5, and the same as in this example, theseinks were ejected using an ink jet apparatus onto a TFT substrate havingbanks 4 consisting of polyimide as shown in FIG. 1.

Immediately after subjecting this substrate to heat treatment on a hotplate for 1 minute at 180° C. in a 2-atmosphere nitrogen environment,pressure was reduced (1 mmHg), the solvent was removed, and aluminescent material layer was achieved. The film thickness of theresulting luminescent layer was 0.08-0.1 μm. In addition, lithiumfluoride (100 nm), calcium (100 nm) and aluminum (150 nm) were depositedin that order on the luminescent layer. The resulting laminate structurewas sealed in epoxy resin, and an organic EL display device wasachieved.

Upon driving the TFT devices provided on each transparent ITO electrode(dot) at 10 volts, it was possible to display a desired color in a pixel(a color equivalent to the luminescent layer provided on this pixel).Further, motion pictures could also be displayed.

Comparative Example 2-1

A composition (R (Red) ink composition) was prepared by mixingluminescent materials with a solvent using the composition shown inTable 3 hereinbelow, and the same as in Example 2-1, an attempt was madeto eject this ink using an ink jet apparatus onto a substrate (TFTsubstrate) having banks 4 consisting of polyimide as shown in FIG. 1.However, clogging occurred in the ink jet heads, making it impossible toform a luminescent layer on the substrate.

TABLE 3 Luminescent Materials Solvents R (Red) ink Compound 7 0.98 gXylene 200 ml Compound 8 0.02 g

Furthermore, compounds 7 & 8, which were the luminescent materials usedin this example, are compounds having the below structures.

Examples of Third Embodiment Example 3-1

First, as compositions, compositions 1-6 (three R (red), G (green) and B(blue) for each composition) were prepared by mixing polymer compoundsas functional materials (luminescent materials) with solvents using theprescriptions shown in Tables 4-9 hereinbelow. As the polymer compounds,compounds were selected from compound 1-compound 5, which are functionalmaterials that are particularly compatible with the third embodiment,and used.

TABLE 4 (Composition 1) Polymer Compounds (1% wt/v) Solvent R (Red)Compound 1 Compound 2 Compound 5 Xylene 0.7 g 0.2 g 0.1 g 100 ml G(Green) Compound 1 Compound 2 Compound 4 Xylene 0.76 g 0.20 g 0.04 g 100ml B (Blue) Compound 1 Compound 2 Compound 3 Xylene 0.78 g 0.15 g 0.07 g100 ml

TABLE 5 (Composition 2) Polymer Compounds (1% wt/v) Solvent R (Red)Compound 1 Compound 2 Compound 5 Mesitylene 0.7 g 0.2 g 0.1 g 100 ml G(Green) Compound 1 Compound 2 Compound 4 Mesitylene 0.76 g 0.20 g 0.04 g100 ml B (Blue) Compound 1 Compound 2 Compound 3 Mesitylene 0.78 g 0.15g 0.07 g 100 ml

TABLE 6 (Composition 3) Polymer Compounds (1% wt/v) Solvent R Compound 1Compound 2 Compound 5 1,2,3,4- (Red) 0.7 g 0.2 g 0.1 gtetramethylbenzene 100 ml G Compound 1 Compound 2 Compound 4 1,2,3,4-(Green) 0.76 g 0.20 g 0.04 g tetramethylbenzene 100 ml B Compound 1Compound 2 Compound 3 1,2,3,4- (Blue) 0.78 g 0.15 g 0.07 gtetramethylbenzene 100 ml

TABLE 7 (Composition 4) Polymer Compounds (1% wt/v) Solvent R (Red)Compound Compound Compound Diethylbenzene 1,2,3,4- 1 0.7 g 2 0.2 g 5 0.1g 30 ml tetramethylbenzene 70 ml G Compound Compound CompoundDiethylbenzene 1,2,3,4- (Green) 1 0.76 g 2 0.20 g 4 0.04 g 30 mltetramethylbenzene 70 ml B (Blue) Compound Compound CompoundDiethylbenzene 1,2,3,4- 1 0.78 g 2 0.15 g 3 0.07 g 30 mltetramethylbenzene 70 ml

TABLE 8 (Composition 5) Polymer Compounds (1% wt/v) Solvent R (Red)Compound Compound Compound Mesitylene Cyclohexylbenzene 1 0.7 g 2 0.2 g5 0.1 g 80 ml 20 ml G Compound Compound Compound MesityleneCyclohexylbenzene (Green) 1 0.76 g 2 0.20 g 4 0.04 g 80 ml 20 ml B(Blue) Compound Compound Compound Mesitylene Cyclohexylbenzene 1 0.78 g2 0.15 g 3 0.07 g 80 ml 20 ml

TABLE 9 (Composition 6) Polymer Compounds (1% wt/v) Solvent R (Red)Compound Compound Compound Dodecylbenzene 1,2,3,4- 1 0.7 g 2 0.2 g 5 0.1g 30 ml tetramethylbenzene 70 ml G Compound Compound CompoundDodecylbenzene 1,2,3,4- (Green) 1 0.76 g 2 0.20 g 4 0.04 g 30 mltetramethylbenzene 70 ml B (Blue) Compound Compound CompoundDodecylbenzene 1,2,3,4- 1 0.78 g 2 0.15 g 3 0.07 g 30 mltetramethylbenzene 70 ml

Furthermore, the vapor pressure (room temperature) of the solventsutilized in compositions 1-6 are as shown below.

Xylene: 13.80 Mesitylene: 1.73

1,2,3,4-tetramethylbenzene: 0.23

Diethylbenzene: 0.70 Cyclohexylbenzene: 0.193 Dodecylbenzene: 0.0000125

Assessments of solution stability, properties of ejecting, and phaseseparation, respectively, for the above-mentioned compositions werecarried out in accordance with the assessment criteria hereinbelow. Theresults of these assessments are shown in Table 10.

Solution stability: Assessed by determining whether or not precipitationwas evident (whether or not there was a change in turbidity) when acomposition was left standing at room temperature for more than two daysfrom time of preparation. Furthermore, turbidity changes were evident at650 nm for G, B compositions, and turbidity changes were evident at 700nm for R compositions.

O: No turbidity change (Transparent solution)X: Change in turbidity (Precipitation occurred)

Properties of ejecting: The flights of composition (ink) droplets from apiezoelectric drive ink jet head (Epson MJ-930C) were observed.

⊚: Extremely goodO: Good (Slight curvature of flight, but patterning can be performed)X: Flight curves and nozzle clogging occurs

Phase separation: Assessed using either the photoluminescence (PL) or ELluminescence spectrum of a naturally dried film after patterning in eachof the R, G, B colors.

O: Compound 1 original short wavelength spectrum not observedX: Compound 1 original short wavelength spectrum observed

TABLE 10 Properties Solution of Phase Composition Stability ejectingSeparation Comparative 1 (R, G, B) ◯ X — Product Present 2 (R, G, B) ◯ ◯◯ Invention 3 (R, G, B) ◯ ⊚ ◯ Product 4 (R, G, B) ◯ ⊚ ◯ 5 (R, G, B) ◯ ⊚◯ 6 (R, G, B) ◯ ⊚ X

However, for composition 6, using the same conditions as in Examples 2-1through 2-6, phase separation became “O” in accordance with either heattreatment or heat treatment under applying pressure followingdispensing.

Example 3-2 Substrate Formation

A substrate having pixels, which are shown in FIG. 2(A) was formed asexplained hereinbelow. On a TFT substrate 11, ITO 12, SiO₂ 13 andpolyimide 14 were formed into a pattern using a photolithography method.This SiO₂ and polyimide are portions constituting banks. At this time,by providing a circular opening portion of 28 μmφ in the SiO₂, and alsoproviding a circular opening portion of 32 μmφ in the polyimide on topthereof, circular pixels 15 comprising these two opening portions wereformed. The pitch α of these pixels is 70.5 μm. The above-mentionedpixels, which are partitioned by SiO₂ and polyimide, constitute theportions to which a dispensing composition containing thebelow-described organic EL material are applied for performingpatterning using an ink jet system.

Plasma Processing of Substrate

Next, O₂ and CF₄ continuous atmospheric pressure plasma processes werecarried out in the direction of the arrows of FIG. 2(B) on theabove-mentioned substrate in which circular pixels had been formed. Theconditions of these plasma processes were as follows. That is, underatmospheric pressure, the power was set to 300 W, and the distancebetween the electrode and the substrate was set at 1 mm. Further, forthe O₂ plasma, the O₂ gas flow was 80 ccm, the helium gas flow was101/min, and the table conveyance rate was set at 10 mm/s, and for theCF₄ plasma, the CF₄ gas flow was 100 ccm, the helium gas flow was101/min, and the table conveyance rate was set at 5 mm/s.

Hole Injection/Transport Layer Formation Using Ink Jet System

Compositions consisting of the compositions shown in Table 11 wereprepared as ink compositions for a hole injection/transport layer.

TABLE 11 Material Content (wt %) Polyethylene 11.08dioxythiophene/polystyrene sulfonic acid mixture Polystyrene sulfonicacid 1.44 Isopropyl alcohol 10 N-methylpyrolidone 27.48 1,3-dimethyl-2-50 imidazolidinone

As shown in FIG. 2(C), the ink composition 17 for the above-mentionedhole injection/transport layer was ejected at 20 pl from an ink jet head(Epson MJ-930C head) 16, and patterning was performed on each pixelelectrode. After patterning, the solvent was removed under conditions ofroom temperature for 20 minutes in a vacuum (1 Torr), and thereafter, ahole injection/transport layer 18 was formed out-of-vacuum via heattreatment for 10 minutes at 200° C. (on a hot plate) (Refer to FIG.2(D)). The film thickness of the resulting hole injection/transportlayer 18 was 40 nm.

Formation of Luminescent Layer Using Ink Jet System

As shown in FIGS. 3 (E) and (F), in accordance with dispensingcomposition 2 of Table 5, which was utilized in the above-mentionedExample 3-1, from an ink jet head (Epson MJ-930C) 16 at 20 pl as thecomposition 19 for a luminescent layer, and performing patterning oneach pixel electrode in B, R, G order, a luminescent layer 20 of eachcolor was formed (Refer to FIG. 3 (G)). After forming the luminescentlayers 20, post baking was performed at 60° C. for 30 minutes underreduced pressure of less than 1 Torr.

Electrode/Sealing Processes

After forming the luminescent layers, an electrode (negative electrode)21 was formed by depositing lithium fluoride (thickness: 2 nm), calcium(thickness: 20 nm), and aluminum (thickness: 20 nm). Finally, theabove-mentioned electrode was sealed with an epoxy resin 22, and a colororganic EL panel 10 was produced (Refer to FIG. 3 (H)).

Example 3-3

Besides forming luminescent layers of each color by using composition 3of Table 6, which was utilized in the above-mentioned Example 3-1, acolor organic EL panel was produced using the same processes as in theabove-mentioned Example 3-2.

Example 3-4

Besides forming luminescent layers of each color by using composition 4of Table 7, which was utilized in the above-mentioned Example 3-1, acolor organic EL panel was produced using the same processes as in theabove-mentioned Example 3-2.

Example 3-5

Besides forming luminescent layers of each color by using composition 5of Table 8, which was utilized in the above-mentioned Example 3-1, acolor organic EL panel was produced using the same processes as in theabove-mentioned Example 3-2.

INDUSTRIAL APPLICABILITY

As explained hereinabove, a composition of the present invention can beused in an ink jet printing method instead of a photolithography method,which is the conventional functional material patterning method, canuse, as a functional material, either a non-polar or a weakly polarmaterial, or a material that is reactive with water, and can preventclogging at dispensing time, achieve stable dispensing, and preventprecipitation of content matter during dispensing and phase separationat film formation following dispensing.

Further, a functional film of the present invention is a uniform,homogenous, micro film, which is formed using the above-mentionedcomposition. Further, a display device of the present invention is anoutstanding display device such as an organic EL device, which iscomprised by providing a luminescent material layer formed using theabove-mentioned composition, and which is especially useful in luminousdisplay applications.

Further, according to the manufacturing method of the display device ofthe present invention, it is possible to easily achieve an array offilms having different functions. Further, because a required amount ofmaterial is used in a required part, it is possible to use less materialthan in methods according to spin coating methods.

1. A method of manufacturing an organic electroluminescent device, themethod comprising: forming a first electrode; forming a first layer froma first composition by applying the first composition above the firstelectrode, the first composition including a polar solvent; and forminga second layer from a second composition by applying the secondcomposition above the first layer, the second composition including anon-polar solvent.
 2. The method of manufacturing the electroluminescentdevice according to claim 1, the non-polar solvent having a lowerpolarity than the polarity of the polar solvent.
 3. The method ofmanufacturing the electroluminescent device according to claim 1, thenon-polar solvent including at least one benzene derivative having 1 ormore substituents, and these substituents having 3 or more carbon atomsin total.
 4. The method of manufacturing the electroluminescent deviceaccording to claim 3, the at least one benzene derivative being selectedfrom a group consisting of cumene, cymene, cyclohexylbenzene,dodecylbenzene, diethylbenzene, pentylbenzene, dipentylbenzene,butylbenzene, tetralin, and tetramethylbenzene.
 5. The method ofmanufacturing the electroluminescent device according to claim 3, the atleast one benzene derivative being dodecylbenzene.
 6. The method ofmanufacturing the electroluminescent device according to claim 5, thenon-polar solvent further including at least one solvent selected from agroup consisting of cymene, tetralin, cumenem, declain, durene,cyclohexylbenzene, dihexylbenzene, tetramethylbenzene anddibutylbenzene.
 7. The method of manufacturing the electroluminescentdevice according to claim 1, the polar solvent including at least onesolvent selected from a group consisting of alpha-butyrolactone,N-methylpyrolidone, 1,3-dimethyl-2-imidazolidinone derivative, glycolethers.
 8. The method of manufacturing the electroluminescent deviceaccording to claim 1, the first layer being a hole injection layer. 9.The method of manufacturing the electroluminescent device according toclaim 1, the second layer being a light emitting layer.
 10. The methodof manufacturing the electroluminescent device according to claim 1, thefirst electrode being a pixel electrode.
 11. A method of manufacturingan organic electroluminescent device, the method comprising: forming afirst electrode; forming a hole injection layer from a first compositionby applying the first composition above the first electrode, the firstcomposition including a first solvent; forming a light emitting layerfrom a second composition by applying the second composition above thefirst layer, the second composition including a second solvent which hasa lower polarity than the polarity of the first solvent.
 12. The methodof manufacturing the electroluminescent device according to claim 11,the second solvent including at least one benzene derivative having 1 ormore substituents, and these substituents having 3 or more carbon atomsin total.
 13. The method of manufacturing the electroluminescent deviceaccording to claim 11, the at least one benzene derivative beingselected from a group consisting of cumene, cymene, cyclohexylbenzene,dodecylbenzene, diethylbenzene, pentylbenzene, dipentylbenzene,butylbenzene, tetralin, and tetramethylbenzene.
 14. The method ofmanufacturing the electroluminescent device according to claim 11, theat least one benzene derivative being dodecylbenzene.
 15. The method ofmanufacturing the electroluminescent device according to claim 14, thesecond solvent further including at least one solvent selected from agroup consisting of cymene, tetralin, cumenem, declain, durene,cyclohexylbenzene, dihexylbenzene, tetramethylbenzene anddibutylbenzene.
 16. The method of manufacturing the electroluminescentdevice according to claim 11, the first solvent including at least onesolvent selected from a group consisting of alpha-butyrolactone,N-methylpyrolidone, 1,3-dimethyl-2-imidazolidinone derivative, glycolethers.
 17. The method of manufacturing the electroluminescent deviceaccording to claim 11, the first electrode being a pixel electrode.